lib: establish Zircon libc++ and KTL foundation

1 files changed, 2386 insertions, 0 deletions

diff --git a/third_party/libcxx/include/c++/v1/__tree b/third_party/libcxx/include/c++/v1/__tree
new file mode 100644
index 0000000..bb8c4f3
--- /dev/null
+++ b/third_party/libcxx/include/c++/v1/__tree
@@ -0,0 +1,2386 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TREE
+#define _LIBCPP___TREE
+
+#include <__algorithm/min.h>
+#include <__algorithm/specialized_algorithms.h>
+#include <__assert>
+#include <__config>
+#include <__fwd/pair.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/next.h>
+#include <__memory/addressof.h>
+#include <__memory/allocator_traits.h>
+#include <__memory/compressed_pair.h>
+#include <__memory/construct_at.h>
+#include <__memory/pointer_traits.h>
+#include <__memory/swap_allocator.h>
+#include <__memory/unique_ptr.h>
+#include <__new/launder.h>
+#include <__type_traits/copy_cvref.h>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/invoke.h>
+#include <__type_traits/is_constructible.h>
+#include <__type_traits/is_nothrow_assignable.h>
+#include <__type_traits/is_nothrow_constructible.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/is_specialization.h>
+#include <__type_traits/is_swappable.h>
+#include <__type_traits/make_transparent.h>
+#include <__type_traits/remove_const.h>
+#include <__type_traits/remove_cvref.h>
+#include <__utility/forward.h>
+#include <__utility/lazy_synth_three_way_comparator.h>
+#include <__utility/move.h>
+#include <__utility/pair.h>
+#include <__utility/swap.h>
+#include <__utility/try_key_extraction.h>
+#include <limits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_DIAGNOSTIC_PUSH
+// GCC complains about the backslashes at the end, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121528
+_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wcomment")
+// __tree is a red-black-tree implementation used for the associative containers (i.e. (multi)map/set). It stores
+// - (1) a pointer to the node with the smallest (i.e. leftmost) element, namely __begin_node_
+// - (2) the number of nodes in the tree, namely __size_
+// - (3) a pointer to the root of the tree, namely __end_node_
+//
+// Storing (1) and (2) is required to allow for constant time lookups. A tree looks like this in memory:
+//
+//      __end_node_
+//           |
+//          root
+//         /    \
+//       l1       r1
+//      /  \     /  \
+//    ...  ... ...  ...
+//
+// All nodes except __end_node_ have a __left_ and __right_ pointer as well as a __parent_ pointer.
+// __end_node_ only contains a __left_ pointer, which points to the root of the tree.
+// This layout allows for iteration through the tree without a need for special handling of the end node. See
+// __tree_next_iter and __tree_prev_iter for more details.
+_LIBCPP_DIAGNOSTIC_POP
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Pointer>
+class __tree_end_node;
+template <class _VoidPtr>
+class __tree_node_base;
+template <class _Tp, class _VoidPtr>
+class __tree_node;
+
+template <class _Key, class _Value>
+struct __value_type;
+
+/*
+
+_NodePtr algorithms
+
+The algorithms taking _NodePtr are red black tree algorithms.  Those
+algorithms taking a parameter named __root should assume that __root
+points to a proper red black tree (unless otherwise specified).
+
+Each algorithm herein assumes that __root->__parent_ points to a non-null
+structure which has a member __left_ which points back to __root.  No other
+member is read or written to at __root->__parent_.
+
+__root->__parent_ will be referred to below (in comments only) as end_node.
+end_node->__left_ is an externably accessible lvalue for __root, and can be
+changed by node insertion and removal (without explicit reference to end_node).
+
+All nodes (with the exception of end_node), even the node referred to as
+__root, have a non-null __parent_ field.
+
+*/
+
+// Returns:  true if __x is a left child of its parent, else false
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+inline _LIBCPP_HIDE_FROM_ABI bool __tree_is_left_child(_NodePtr __x) _NOEXCEPT {
+  return __x == __x->__parent_->__left_;
+}
+
+// Determines if the subtree rooted at __x is a proper red black subtree.  If
+//    __x is a proper subtree, returns the black height (null counts as 1).  If
+//    __x is an improper subtree, returns 0.
+template <class _NodePtr>
+unsigned __tree_sub_invariant(_NodePtr __x) {
+  if (__x == nullptr)
+    return 1;
+  // parent consistency checked by caller
+  // check __x->__left_ consistency
+  if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x)
+    return 0;
+  // check __x->__right_ consistency
+  if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x)
+    return 0;
+  // check __x->__left_ != __x->__right_ unless both are nullptr
+  if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr)
+    return 0;
+  // If this is red, neither child can be red
+  if (!__x->__is_black_) {
+    if (__x->__left_ && !__x->__left_->__is_black_)
+      return 0;
+    if (__x->__right_ && !__x->__right_->__is_black_)
+      return 0;
+  }
+  unsigned __h = std::__tree_sub_invariant(__x->__left_);
+  if (__h == 0)
+    return 0; // invalid left subtree
+  if (__h != std::__tree_sub_invariant(__x->__right_))
+    return 0;                    // invalid or different height right subtree
+  return __h + __x->__is_black_; // return black height of this node
+}
+
+// Determines if the red black tree rooted at __root is a proper red black tree.
+//    __root == nullptr is a proper tree.  Returns true if __root is a proper
+//    red black tree, else returns false.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI bool __tree_invariant(_NodePtr __root) {
+  if (__root == nullptr)
+    return true;
+  // check __x->__parent_ consistency
+  if (__root->__parent_ == nullptr)
+    return false;
+  if (!std::__tree_is_left_child(__root))
+    return false;
+  // root must be black
+  if (!__root->__is_black_)
+    return false;
+  // do normal node checks
+  return std::__tree_sub_invariant(__root) != 0;
+}
+
+// Returns:  pointer to the left-most node under __x.
+template <class _NodePtr>
+inline _LIBCPP_HIDE_FROM_ABI _NodePtr __tree_min(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "Root node shouldn't be null");
+  while (__x->__left_ != nullptr)
+    __x = __x->__left_;
+  return __x;
+}
+
+// Returns:  pointer to the right-most node under __x.
+template <class _NodePtr>
+inline _LIBCPP_HIDE_FROM_ABI _NodePtr __tree_max(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "Root node shouldn't be null");
+  while (__x->__right_ != nullptr)
+    __x = __x->__right_;
+  return __x;
+}
+
+// Returns:  pointer to the next in-order node after __x.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI _NodePtr __tree_next(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  if (__x->__right_ != nullptr)
+    return std::__tree_min(__x->__right_);
+  while (!std::__tree_is_left_child(__x))
+    __x = __x->__parent_unsafe();
+  return __x->__parent_unsafe();
+}
+
+// __tree_next_iter and __tree_prev_iter implement iteration through the tree. The order is as follows:
+// left sub-tree -> node -> right sub-tree. When the right-most node of a sub-tree is reached, we walk up the tree until
+// we find a node where we were in the left sub-tree. We are _always_ in a left sub-tree, since the __end_node_ points
+// to the actual root of the tree through a __left_ pointer. Incrementing the end() pointer is UB, so we can assume that
+// never happens.
+template <class _EndNodePtr, class _NodePtr>
+inline _LIBCPP_HIDE_FROM_ABI _EndNodePtr __tree_next_iter(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  if (__x->__right_ != nullptr)
+    return std::__static_fancy_pointer_cast<_EndNodePtr>(std::__tree_min(__x->__right_));
+  while (!std::__tree_is_left_child(__x))
+    __x = __x->__parent_unsafe();
+  return std::__static_fancy_pointer_cast<_EndNodePtr>(__x->__parent_);
+}
+
+// Returns:  pointer to the previous in-order node before __x.
+// Note: __x may be the end node.
+template <class _NodePtr, class _EndNodePtr>
+inline _LIBCPP_HIDE_FROM_ABI _NodePtr __tree_prev_iter(_EndNodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  if (__x->__left_ != nullptr)
+    return std::__tree_max(__x->__left_);
+  _NodePtr __xx = std::__static_fancy_pointer_cast<_NodePtr>(__x);
+  while (std::__tree_is_left_child(__xx))
+    __xx = __xx->__parent_unsafe();
+  return __xx->__parent_unsafe();
+}
+
+// Returns:  pointer to a node which has no children
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI _NodePtr __tree_leaf(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  while (true) {
+    if (__x->__left_ != nullptr) {
+      __x = __x->__left_;
+      continue;
+    }
+    if (__x->__right_ != nullptr) {
+      __x = __x->__right_;
+      continue;
+    }
+    break;
+  }
+  return __x;
+}
+
+// Effects:  Makes __x->__right_ the subtree root with __x as its left child
+//           while preserving in-order order.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI void __tree_left_rotate(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  _LIBCPP_ASSERT_INTERNAL(__x->__right_ != nullptr, "node should have a right child");
+  _NodePtr __y  = __x->__right_;
+  __x->__right_ = __y->__left_;
+  if (__x->__right_ != nullptr)
+    __x->__right_->__set_parent(__x);
+  __y->__parent_ = __x->__parent_;
+  if (std::__tree_is_left_child(__x))
+    __x->__parent_->__left_ = __y;
+  else
+    __x->__parent_unsafe()->__right_ = __y;
+  __y->__left_ = __x;
+  __x->__set_parent(__y);
+}
+
+// Effects:  Makes __x->__left_ the subtree root with __x as its right child
+//           while preserving in-order order.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI void __tree_right_rotate(_NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "node shouldn't be null");
+  _LIBCPP_ASSERT_INTERNAL(__x->__left_ != nullptr, "node should have a left child");
+  _NodePtr __y = __x->__left_;
+  __x->__left_ = __y->__right_;
+  if (__x->__left_ != nullptr)
+    __x->__left_->__set_parent(__x);
+  __y->__parent_ = __x->__parent_;
+  if (std::__tree_is_left_child(__x))
+    __x->__parent_->__left_ = __y;
+  else
+    __x->__parent_unsafe()->__right_ = __y;
+  __y->__right_ = __x;
+  __x->__set_parent(__y);
+}
+
+// Effects:  Rebalances __root after attaching __x to a leaf.
+// Precondition:  __x has no children.
+//                __x == __root or == a direct or indirect child of __root.
+//                If __x were to be unlinked from __root (setting __root to
+//                  nullptr if __root == __x), __tree_invariant(__root) == true.
+// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_
+//                may be different than the value passed in as __root.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI void __tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__root != nullptr, "Root of the tree shouldn't be null");
+  _LIBCPP_ASSERT_INTERNAL(__x != nullptr, "Can't attach null node to a leaf");
+  __x->__is_black_ = __x == __root;
+  while (__x != __root && !__x->__parent_unsafe()->__is_black_) {
+    // __x->__parent_ != __root because __x->__parent_->__is_black == false
+    if (std::__tree_is_left_child(__x->__parent_unsafe())) {
+      _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_;
+      if (__y != nullptr && !__y->__is_black_) {
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = true;
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = __x == __root;
+        __y->__is_black_ = true;
+      } else {
+        if (!std::__tree_is_left_child(__x)) {
+          __x = __x->__parent_unsafe();
+          std::__tree_left_rotate(__x);
+        }
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = true;
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = false;
+        std::__tree_right_rotate(__x);
+        break;
+      }
+    } else {
+      _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_;
+      if (__y != nullptr && !__y->__is_black_) {
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = true;
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = __x == __root;
+        __y->__is_black_ = true;
+      } else {
+        if (std::__tree_is_left_child(__x)) {
+          __x = __x->__parent_unsafe();
+          std::__tree_right_rotate(__x);
+        }
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = true;
+        __x              = __x->__parent_unsafe();
+        __x->__is_black_ = false;
+        std::__tree_left_rotate(__x);
+        break;
+      }
+    }
+  }
+}
+
+// Precondition:  __z == __root or == a direct or indirect child of __root.
+// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed.
+// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_
+//                nor any of its children refer to __z.  end_node->__left_
+//                may be different than the value passed in as __root.
+template <class _NodePtr>
+_LIBCPP_HIDE_FROM_ABI void __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__root != nullptr, "Root node should not be null");
+  _LIBCPP_ASSERT_INTERNAL(__z != nullptr, "The node to remove should not be null");
+  _LIBCPP_ASSERT_INTERNAL(std::__tree_invariant(__root), "The tree invariants should hold");
+  // __z will be removed from the tree.  Client still needs to destruct/deallocate it
+  // __y is either __z, or if __z has two children, __tree_next(__z).
+  // __y will have at most one child.
+  // __y will be the initial hole in the tree (make the hole at a leaf)
+  _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ? __z : std::__tree_next(__z);
+  // __x is __y's possibly null single child
+  _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_;
+  // __w is __x's possibly null uncle (will become __x's sibling)
+  _NodePtr __w = nullptr;
+  // link __x to __y's parent, and find __w
+  if (__x != nullptr)
+    __x->__parent_ = __y->__parent_;
+  if (std::__tree_is_left_child(__y)) {
+    __y->__parent_->__left_ = __x;
+    if (__y != __root)
+      __w = __y->__parent_unsafe()->__right_;
+    else
+      __root = __x; // __w == nullptr
+  } else {
+    __y->__parent_unsafe()->__right_ = __x;
+    // __y can't be root if it is a right child
+    __w = __y->__parent_->__left_;
+  }
+  bool __removed_black = __y->__is_black_;
+  // If we didn't remove __z, do so now by splicing in __y for __z,
+  //    but copy __z's color.  This does not impact __x or __w.
+  if (__y != __z) {
+    // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr
+    __y->__parent_ = __z->__parent_;
+    if (std::__tree_is_left_child(__z))
+      __y->__parent_->__left_ = __y;
+    else
+      __y->__parent_unsafe()->__right_ = __y;
+    __y->__left_ = __z->__left_;
+    __y->__left_->__set_parent(__y);
+    __y->__right_ = __z->__right_;
+    if (__y->__right_ != nullptr)
+      __y->__right_->__set_parent(__y);
+    __y->__is_black_ = __z->__is_black_;
+    if (__root == __z)
+      __root = __y;
+  }
+  // There is no need to rebalance if we removed a red, or if we removed
+  //     the last node.
+  if (__removed_black && __root != nullptr) {
+    // Rebalance:
+    // __x has an implicit black color (transferred from the removed __y)
+    //    associated with it, no matter what its color is.
+    // If __x is __root (in which case it can't be null), it is supposed
+    //    to be black anyway, and if it is doubly black, then the double
+    //    can just be ignored.
+    // If __x is red (in which case it can't be null), then it can absorb
+    //    the implicit black just by setting its color to black.
+    // Since __y was black and only had one child (which __x points to), __x
+    //   is either red with no children, else null, otherwise __y would have
+    //   different black heights under left and right pointers.
+    // if (__x == __root || __x != nullptr && !__x->__is_black_)
+    if (__x != nullptr)
+      __x->__is_black_ = true;
+    else {
+      //  Else __x isn't root, and is "doubly black", even though it may
+      //     be null.  __w can not be null here, else the parent would
+      //     see a black height >= 2 on the __x side and a black height
+      //     of 1 on the __w side (__w must be a non-null black or a red
+      //     with a non-null black child).
+      while (true) {
+        if (!std::__tree_is_left_child(__w)) // if x is left child
+        {
+          if (!__w->__is_black_) {
+            __w->__is_black_                    = true;
+            __w->__parent_unsafe()->__is_black_ = false;
+            std::__tree_left_rotate(__w->__parent_unsafe());
+            // __x is still valid
+            // reset __root only if necessary
+            if (__root == __w->__left_)
+              __root = __w;
+            // reset sibling, and it still can't be null
+            __w = __w->__left_->__right_;
+          }
+          // __w->__is_black_ is now true, __w may have null children
+          if ((__w->__left_ == nullptr || __w->__left_->__is_black_) &&
+              (__w->__right_ == nullptr || __w->__right_->__is_black_)) {
+            __w->__is_black_ = false;
+            __x              = __w->__parent_unsafe();
+            // __x can no longer be null
+            if (__x == __root || !__x->__is_black_) {
+              __x->__is_black_ = true;
+              break;
+            }
+            // reset sibling, and it still can't be null
+            __w = std::__tree_is_left_child(__x) ? __x->__parent_unsafe()->__right_ : __x->__parent_->__left_;
+            // continue;
+          } else // __w has a red child
+          {
+            if (__w->__right_ == nullptr || __w->__right_->__is_black_) {
+              // __w left child is non-null and red
+              __w->__left_->__is_black_ = true;
+              __w->__is_black_          = false;
+              std::__tree_right_rotate(__w);
+              // __w is known not to be root, so root hasn't changed
+              // reset sibling, and it still can't be null
+              __w = __w->__parent_unsafe();
+            }
+            // __w has a right red child, left child may be null
+            __w->__is_black_                    = __w->__parent_unsafe()->__is_black_;
+            __w->__parent_unsafe()->__is_black_ = true;
+            __w->__right_->__is_black_          = true;
+            std::__tree_left_rotate(__w->__parent_unsafe());
+            break;
+          }
+        } else {
+          if (!__w->__is_black_) {
+            __w->__is_black_                    = true;
+            __w->__parent_unsafe()->__is_black_ = false;
+            std::__tree_right_rotate(__w->__parent_unsafe());
+            // __x is still valid
+            // reset __root only if necessary
+            if (__root == __w->__right_)
+              __root = __w;
+            // reset sibling, and it still can't be null
+            __w = __w->__right_->__left_;
+          }
+          // __w->__is_black_ is now true, __w may have null children
+          if ((__w->__left_ == nullptr || __w->__left_->__is_black_) &&
+              (__w->__right_ == nullptr || __w->__right_->__is_black_)) {
+            __w->__is_black_ = false;
+            __x              = __w->__parent_unsafe();
+            // __x can no longer be null
+            if (!__x->__is_black_ || __x == __root) {
+              __x->__is_black_ = true;
+              break;
+            }
+            // reset sibling, and it still can't be null
+            __w = std::__tree_is_left_child(__x) ? __x->__parent_unsafe()->__right_ : __x->__parent_->__left_;
+            // continue;
+          } else // __w has a red child
+          {
+            if (__w->__left_ == nullptr || __w->__left_->__is_black_) {
+              // __w right child is non-null and red
+              __w->__right_->__is_black_ = true;
+              __w->__is_black_           = false;
+              std::__tree_left_rotate(__w);
+              // __w is known not to be root, so root hasn't changed
+              // reset sibling, and it still can't be null
+              __w = __w->__parent_unsafe();
+            }
+            // __w has a left red child, right child may be null
+            __w->__is_black_                    = __w->__parent_unsafe()->__is_black_;
+            __w->__parent_unsafe()->__is_black_ = true;
+            __w->__left_->__is_black_           = true;
+            std::__tree_right_rotate(__w->__parent_unsafe());
+            break;
+          }
+        }
+      }
+    }
+  }
+}
+
+// node traits
+
+template <class _Tp>
+inline const bool __is_tree_value_type_v = __is_specialization_v<_Tp, __value_type>;
+
+template <class _Tp>
+struct __get_tree_key_type {
+  using type _LIBCPP_NODEBUG = _Tp;
+};
+
+template <class _Key, class _ValueT>
+struct __get_tree_key_type<__value_type<_Key, _ValueT> > {
+  using type _LIBCPP_NODEBUG = _Key;
+};
+
+template <class _Tp>
+using __get_tree_key_type_t _LIBCPP_NODEBUG = typename __get_tree_key_type<_Tp>::type;
+
+template <class _Tp>
+struct __get_node_value_type {
+  using type _LIBCPP_NODEBUG = _Tp;
+};
+
+template <class _Key, class _ValueT>
+struct __get_node_value_type<__value_type<_Key, _ValueT> > {
+  using type _LIBCPP_NODEBUG = pair<const _Key, _ValueT>;
+};
+
+template <class _Tp>
+using __get_node_value_type_t _LIBCPP_NODEBUG = typename __get_node_value_type<_Tp>::type;
+
+template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
+struct __tree_node_types;
+
+template <class _NodePtr, class _Tp, class _VoidPtr>
+struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> > {
+  using __node_base_pointer _LIBCPP_NODEBUG = __rebind_pointer_t<_VoidPtr, __tree_node_base<_VoidPtr> >;
+  using __end_node_pointer _LIBCPP_NODEBUG  = __rebind_pointer_t<_VoidPtr, __tree_end_node<__node_base_pointer> >;
+
+private:
+  static_assert(is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value,
+                "_VoidPtr does not point to unqualified void type");
+};
+
+// node
+
+template <class _Pointer>
+class __tree_end_node {
+public:
+  using pointer = _Pointer;
+  pointer __left_;
+
+  _LIBCPP_HIDE_FROM_ABI __tree_end_node() _NOEXCEPT : __left_() {}
+};
+
+template <class _VoidPtr>
+class __tree_node_base : public __tree_end_node<__rebind_pointer_t<_VoidPtr, __tree_node_base<_VoidPtr> > > {
+public:
+  using pointer                            = __rebind_pointer_t<_VoidPtr, __tree_node_base>;
+  using __end_node_pointer _LIBCPP_NODEBUG = __rebind_pointer_t<_VoidPtr, __tree_end_node<pointer> >;
+
+  pointer __right_;
+  __end_node_pointer __parent_;
+  bool __is_black_;
+
+  _LIBCPP_HIDE_FROM_ABI pointer __parent_unsafe() const { return std::__static_fancy_pointer_cast<pointer>(__parent_); }
+
+  _LIBCPP_HIDE_FROM_ABI void __set_parent(pointer __p) {
+    __parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__p);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_node_base()             = default;
+  __tree_node_base(__tree_node_base const&)            = delete;
+  __tree_node_base& operator=(__tree_node_base const&) = delete;
+};
+
+template <class _Tp, class _VoidPtr>
+class __tree_node : public __tree_node_base<_VoidPtr> {
+public:
+  using __node_value_type _LIBCPP_NODEBUG = __get_node_value_type_t<_Tp>;
+
+// We use a union to avoid initialization during member initialization, which allows us
+// to use the allocator from the container to construct the `__node_value_type` in the
+// memory provided by the union member
+#ifndef _LIBCPP_CXX03_LANG
+
+private:
+  union {
+    __node_value_type __value_;
+  };
+
+public:
+  _LIBCPP_HIDE_FROM_ABI __node_value_type& __get_value() { return __value_; }
+#else
+
+private:
+  _ALIGNAS_TYPE(__node_value_type) unsigned char __buffer_[sizeof(__node_value_type)];
+
+public:
+  _LIBCPP_HIDE_FROM_ABI __node_value_type& __get_value() { return *reinterpret_cast<__node_value_type*>(__buffer_); }
+#endif
+
+  template <class _Alloc, class... _Args>
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_node(_Alloc& __na, _Args&&... __args) {
+    allocator_traits<_Alloc>::construct(__na, std::addressof(__get_value()), std::forward<_Args>(__args)...);
+  }
+  ~__tree_node()                             = delete;
+  __tree_node(__tree_node const&)            = delete;
+  __tree_node& operator=(__tree_node const&) = delete;
+};
+
+template <class _Allocator>
+class __tree_node_destructor {
+  using allocator_type                 = _Allocator;
+  using __alloc_traits _LIBCPP_NODEBUG = allocator_traits<allocator_type>;
+
+public:
+  using pointer = typename __alloc_traits::pointer;
+
+private:
+  allocator_type& __na_;
+
+public:
+  bool __value_constructed;
+
+  _LIBCPP_HIDE_FROM_ABI __tree_node_destructor(const __tree_node_destructor&) = default;
+  __tree_node_destructor& operator=(const __tree_node_destructor&)            = delete;
+
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT
+      : __na_(__na),
+        __value_constructed(__val) {}
+
+  _LIBCPP_HIDE_FROM_ABI void operator()(pointer __p) _NOEXCEPT {
+    if (__value_constructed)
+      __alloc_traits::destroy(__na_, std::addressof(__p->__get_value()));
+    if (__p)
+      __alloc_traits::deallocate(__na_, __p, 1);
+  }
+
+  template <class>
+  friend class __map_node_destructor;
+};
+
+#if _LIBCPP_STD_VER >= 17
+template <class _NodeType, class _Alloc>
+struct __generic_container_node_destructor;
+template <class _Tp, class _VoidPtr, class _Alloc>
+struct __generic_container_node_destructor<__tree_node<_Tp, _VoidPtr>, _Alloc> : __tree_node_destructor<_Alloc> {
+  using __tree_node_destructor<_Alloc>::__tree_node_destructor;
+};
+#endif
+
+// Do an in-order traversal of the tree until `__break` returns true. Takes the root node of the tree.
+template <class _Reference, class _Break, class _NodePtr, class _Func, class _Proj>
+#ifndef _LIBCPP_COMPILER_GCC // This function is recursive, so GCC complains about always_inline.
+_LIBCPP_HIDE_FROM_ABI
+#endif
+bool __tree_iterate_from_root(_Break __break, _NodePtr __root, _Func& __func, _Proj& __proj) {
+  if (__root->__left_) {
+    if (std::__tree_iterate_from_root<_Reference>(__break, static_cast<_NodePtr>(__root->__left_), __func, __proj))
+      return true;
+  }
+  if (__break(__root))
+    return true;
+  std::__invoke(__func, std::__invoke(__proj, static_cast<_Reference>(__root->__get_value())));
+  if (__root->__right_)
+    return std::__tree_iterate_from_root<_Reference>(__break, static_cast<_NodePtr>(__root->__right_), __func, __proj);
+  return false;
+}
+
+// Do an in-order traversal of the tree from __first to __last.
+template <class _NodeIter, class _Func, class _Proj>
+_LIBCPP_HIDE_FROM_ABI void
+__tree_iterate_subrange(_NodeIter __first_it, _NodeIter __last_it, _Func& __func, _Proj& __proj) {
+  using _NodePtr   = typename _NodeIter::__node_pointer;
+  using _Reference = typename _NodeIter::reference;
+
+  auto __first = __first_it.__ptr_;
+  auto __last  = __last_it.__ptr_;
+
+  while (true) {
+    if (__first == __last)
+      return;
+    const auto __nfirst = static_cast<_NodePtr>(__first);
+    std::__invoke(__func, std::__invoke(__proj, static_cast<_Reference>(__nfirst->__get_value())));
+    if (__nfirst->__right_) {
+      if (std::__tree_iterate_from_root<_Reference>(
+              [&](_NodePtr __node) -> bool { return __node == __last; },
+              static_cast<_NodePtr>(__nfirst->__right_),
+              __func,
+              __proj))
+        return;
+    }
+    while (!std::__tree_is_left_child(static_cast<_NodePtr>(__first)))
+      __first = static_cast<_NodePtr>(__first)->__parent_;
+    __first = static_cast<_NodePtr>(__first)->__parent_;
+  }
+}
+
+template <class _Tp, class _NodePtr, class _DiffType>
+class __tree_iterator {
+  using _NodeTypes _LIBCPP_NODEBUG = __tree_node_types<_NodePtr>;
+  // NOLINTNEXTLINE(libcpp-nodebug-on-aliases) lldb relies on this alias for pretty printing
+  using __node_pointer                      = _NodePtr;
+  using __node_base_pointer _LIBCPP_NODEBUG = typename _NodeTypes::__node_base_pointer;
+  using __end_node_pointer _LIBCPP_NODEBUG  = typename _NodeTypes::__end_node_pointer;
+
+  __end_node_pointer __ptr_;
+
+public:
+  using iterator_category = bidirectional_iterator_tag;
+  using value_type        = __get_node_value_type_t<_Tp>;
+  using difference_type   = _DiffType;
+  using reference         = value_type&;
+  using pointer           = __rebind_pointer_t<_NodePtr, value_type>;
+
+  _LIBCPP_HIDE_FROM_ABI __tree_iterator() _NOEXCEPT : __ptr_(nullptr) {}
+
+  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __get_np()->__get_value(); }
+  _LIBCPP_HIDE_FROM_ABI pointer operator->() const {
+    return pointer_traits<pointer>::pointer_to(__get_np()->__get_value());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_iterator& operator++() {
+    __ptr_ = std::__tree_next_iter<__end_node_pointer>(std::__static_fancy_pointer_cast<__node_base_pointer>(__ptr_));
+    return *this;
+  }
+  _LIBCPP_HIDE_FROM_ABI __tree_iterator operator++(int) {
+    __tree_iterator __t(*this);
+    ++(*this);
+    return __t;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_iterator& operator--() {
+    __ptr_ = std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_prev_iter<__node_base_pointer>(__ptr_));
+    return *this;
+  }
+  _LIBCPP_HIDE_FROM_ABI __tree_iterator operator--(int) {
+    __tree_iterator __t(*this);
+    --(*this);
+    return __t;
+  }
+
+  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const __tree_iterator& __x, const __tree_iterator& __y) {
+    return __x.__ptr_ == __y.__ptr_;
+  }
+  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y) {
+    return !(__x == __y);
+  }
+
+private:
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_iterator(__node_pointer __p) _NOEXCEPT
+      : __ptr_(std::__static_fancy_pointer_cast<__end_node_pointer>(__p)) {}
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __get_np() const {
+    return std::__static_fancy_pointer_cast<__node_pointer>(__ptr_);
+  }
+  template <class, class, class>
+  friend class __tree;
+  template <class, class, class>
+  friend class __tree_const_iterator;
+
+  template <class _NodeIter, class _Func, class _Proj>
+  friend void __tree_iterate_subrange(_NodeIter, _NodeIter, _Func&, _Proj&);
+};
+
+#ifndef _LIBCPP_CXX03_LANG
+// This also handles {multi,}set::iterator, since they're just aliases to __tree::iterator
+template <class _Tp, class _NodePtr, class _DiffType>
+struct __specialized_algorithm<
+    _Algorithm::__for_each,
+    __iterator_pair<__tree_iterator<_Tp, _NodePtr, _DiffType>, __tree_iterator<_Tp, _NodePtr, _DiffType>>> {
+  static const bool __has_algorithm = true;
+
+  using __iterator _LIBCPP_NODEBUG = __tree_iterator<_Tp, _NodePtr, _DiffType>;
+
+  template <class _Func, class _Proj>
+  _LIBCPP_HIDE_FROM_ABI static void operator()(__iterator __first, __iterator __last, _Func& __func, _Proj& __proj) {
+    std::__tree_iterate_subrange(__first, __last, __func, __proj);
+  }
+};
+#endif
+
+template <class _Tp, class _NodePtr, class _DiffType>
+class __tree_const_iterator {
+  using _NodeTypes _LIBCPP_NODEBUG = __tree_node_types<_NodePtr>;
+  // NOLINTNEXTLINE(libcpp-nodebug-on-aliases) lldb relies on this alias for pretty printing
+  using __node_pointer                      = _NodePtr;
+  using __node_base_pointer _LIBCPP_NODEBUG = typename _NodeTypes::__node_base_pointer;
+  using __end_node_pointer _LIBCPP_NODEBUG  = typename _NodeTypes::__end_node_pointer;
+
+  __end_node_pointer __ptr_;
+
+public:
+  using iterator_category                    = bidirectional_iterator_tag;
+  using value_type                           = __get_node_value_type_t<_Tp>;
+  using difference_type                      = _DiffType;
+  using reference                            = const value_type&;
+  using pointer                              = __rebind_pointer_t<_NodePtr, const value_type>;
+  using __non_const_iterator _LIBCPP_NODEBUG = __tree_iterator<_Tp, __node_pointer, difference_type>;
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator() _NOEXCEPT : __ptr_(nullptr) {}
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT : __ptr_(__p.__ptr_) {}
+
+  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __get_np()->__get_value(); }
+  _LIBCPP_HIDE_FROM_ABI pointer operator->() const {
+    return pointer_traits<pointer>::pointer_to(__get_np()->__get_value());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator& operator++() {
+    __ptr_ = std::__tree_next_iter<__end_node_pointer>(std::__static_fancy_pointer_cast<__node_base_pointer>(__ptr_));
+    return *this;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator operator++(int) {
+    __tree_const_iterator __t(*this);
+    ++(*this);
+    return __t;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator& operator--() {
+    __ptr_ = std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_prev_iter<__node_base_pointer>(__ptr_));
+    return *this;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree_const_iterator operator--(int) {
+    __tree_const_iterator __t(*this);
+    --(*this);
+    return __t;
+  }
+
+  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y) {
+    return __x.__ptr_ == __y.__ptr_;
+  }
+  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y) {
+    return !(__x == __y);
+  }
+
+private:
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT
+      : __ptr_(std::__static_fancy_pointer_cast<__end_node_pointer>(__p)) {}
+  _LIBCPP_HIDE_FROM_ABI explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT
+      : __ptr_(std::__static_fancy_pointer_cast<__end_node_pointer>(__p)) {}
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __get_np() const {
+    return std::__static_fancy_pointer_cast<__node_pointer>(__ptr_);
+  }
+
+  template <class, class, class>
+  friend class __tree;
+
+  template <class _NodeIter, class _Func, class _Proj>
+  friend void __tree_iterate_subrange(_NodeIter, _NodeIter, _Func&, _Proj&);
+};
+
+#ifndef _LIBCPP_CXX03_LANG
+// This also handles {multi,}set::const_iterator, since they're just aliases to __tree::iterator
+template <class _Tp, class _NodePtr, class _DiffType>
+struct __specialized_algorithm<
+    _Algorithm::__for_each,
+    __iterator_pair<__tree_const_iterator<_Tp, _NodePtr, _DiffType>, __tree_const_iterator<_Tp, _NodePtr, _DiffType>>> {
+  static const bool __has_algorithm = true;
+
+  using __iterator _LIBCPP_NODEBUG = __tree_const_iterator<_Tp, _NodePtr, _DiffType>;
+
+  template <class _Func, class _Proj>
+  _LIBCPP_HIDE_FROM_ABI static void operator()(__iterator __first, __iterator __last, _Func& __func, _Proj& __proj) {
+    std::__tree_iterate_subrange(__first, __last, __func, __proj);
+  }
+};
+#endif
+
+template <class _Tp, class _Compare>
+#ifndef _LIBCPP_CXX03_LANG
+_LIBCPP_DIAGNOSE_WARNING(!__is_invocable_v<_Compare const&, _Tp const&, _Tp const&>,
+                         "the specified comparator type does not provide a viable const call operator")
+#endif
+int __diagnose_non_const_comparator();
+
+template <class _Tp, class _Compare, class _Allocator>
+class __tree {
+public:
+  using value_type     = __get_node_value_type_t<_Tp>;
+  using value_compare  = _Compare;
+  using allocator_type = _Allocator;
+
+private:
+  using __alloc_traits _LIBCPP_NODEBUG = allocator_traits<allocator_type>;
+  using key_type                       = __get_tree_key_type_t<_Tp>;
+
+public:
+  using pointer         = typename __alloc_traits::pointer;
+  using const_pointer   = typename __alloc_traits::const_pointer;
+  using size_type       = typename __alloc_traits::size_type;
+  using difference_type = typename __alloc_traits::difference_type;
+
+  using __void_pointer _LIBCPP_NODEBUG = typename __alloc_traits::void_pointer;
+
+  using __node _LIBCPP_NODEBUG = __tree_node<_Tp, __void_pointer>;
+  // NOLINTNEXTLINE(libcpp-nodebug-on-aliases) lldb relies on this alias for pretty printing
+  using __node_pointer = __rebind_pointer_t<__void_pointer, __node>;
+
+  using __node_base _LIBCPP_NODEBUG         = __tree_node_base<__void_pointer>;
+  using __node_base_pointer _LIBCPP_NODEBUG = __rebind_pointer_t<__void_pointer, __node_base>;
+
+  using __end_node_t _LIBCPP_NODEBUG       = __tree_end_node<__node_base_pointer>;
+  using __end_node_pointer _LIBCPP_NODEBUG = __rebind_pointer_t<__void_pointer, __end_node_t>;
+
+  using __node_allocator _LIBCPP_NODEBUG = __rebind_alloc<__alloc_traits, __node>;
+  using __node_traits _LIBCPP_NODEBUG    = allocator_traits<__node_allocator>;
+
+private:
+  // check for sane allocator pointer rebinding semantics. Rebinding the
+  // allocator for a new pointer type should be exactly the same as rebinding
+  // the pointer using 'pointer_traits'.
+  static_assert(is_same<__node_pointer, typename __node_traits::pointer>::value,
+                "Allocator does not rebind pointers in a sane manner.");
+  using __node_base_allocator _LIBCPP_NODEBUG = __rebind_alloc<__node_traits, __node_base>;
+  using __node_base_traits _LIBCPP_NODEBUG    = allocator_traits<__node_base_allocator>;
+  static_assert(is_same<__node_base_pointer, typename __node_base_traits::pointer>::value,
+                "Allocator does not rebind pointers in a sane manner.");
+
+private:
+  __end_node_pointer __begin_node_;
+  _LIBCPP_COMPRESSED_PAIR(__end_node_t, __end_node_, __node_allocator, __node_alloc_);
+  _LIBCPP_COMPRESSED_PAIR(size_type, __size_, value_compare, __value_comp_);
+
+public:
+  _LIBCPP_HIDE_FROM_ABI __end_node_pointer __end_node() _NOEXCEPT {
+    return pointer_traits<__end_node_pointer>::pointer_to(__end_node_);
+  }
+  _LIBCPP_HIDE_FROM_ABI __end_node_pointer __end_node() const _NOEXCEPT {
+    return pointer_traits<__end_node_pointer>::pointer_to(const_cast<__end_node_t&>(__end_node_));
+  }
+  _LIBCPP_HIDE_FROM_ABI __node_allocator& __node_alloc() _NOEXCEPT { return __node_alloc_; }
+
+private:
+  _LIBCPP_HIDE_FROM_ABI const __node_allocator& __node_alloc() const _NOEXCEPT { return __node_alloc_; }
+
+public:
+  _LIBCPP_HIDE_FROM_ABI allocator_type __alloc() const _NOEXCEPT { return allocator_type(__node_alloc()); }
+
+  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __size_; }
+  _LIBCPP_HIDE_FROM_ABI value_compare& value_comp() _NOEXCEPT { return __value_comp_; }
+  _LIBCPP_HIDE_FROM_ABI const value_compare& value_comp() const _NOEXCEPT { return __value_comp_; }
+
+public:
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __root() const _NOEXCEPT {
+    return std::__static_fancy_pointer_cast<__node_pointer>(__end_node()->__left_);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __node_base_pointer* __root_ptr() const _NOEXCEPT {
+    return std::addressof(__end_node()->__left_);
+  }
+
+  using iterator       = __tree_iterator<_Tp, __node_pointer, difference_type>;
+  using const_iterator = __tree_const_iterator<_Tp, __node_pointer, difference_type>;
+
+  _LIBCPP_HIDE_FROM_ABI explicit __tree(const value_compare& __comp) _NOEXCEPT_(
+      is_nothrow_default_constructible<__node_allocator>::value&& is_nothrow_copy_constructible<value_compare>::value)
+      : __size_(0), __value_comp_(__comp) {
+    __begin_node_ = __end_node();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI explicit __tree(const allocator_type& __a)
+      : __begin_node_(), __node_alloc_(__node_allocator(__a)), __size_(0) {
+    __begin_node_ = __end_node();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree(const value_compare& __comp, const allocator_type& __a)
+      : __begin_node_(), __node_alloc_(__node_allocator(__a)), __size_(0), __value_comp_(__comp) {
+    __begin_node_ = __end_node();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree(const __tree& __t);
+
+  _LIBCPP_HIDE_FROM_ABI __tree(const __tree& __other, const allocator_type& __alloc)
+      : __begin_node_(__end_node()), __node_alloc_(__alloc), __size_(0), __value_comp_(__other.value_comp()) {
+    if (__other.size() == 0)
+      return;
+
+    *__root_ptr() = std::__static_fancy_pointer_cast<__node_base_pointer>(__copy_construct_tree(__other.__root()));
+    __root()->__parent_ = __end_node();
+    __begin_node_       = std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__end_node()->__left_));
+    __size_             = __other.size();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __tree& operator=(const __tree& __t);
+  template <class _ForwardIterator>
+  _LIBCPP_HIDE_FROM_ABI void __assign_unique(_ForwardIterator __first, _ForwardIterator __last);
+  _LIBCPP_HIDE_FROM_ABI __tree(__tree&& __t) _NOEXCEPT_(
+      is_nothrow_move_constructible<__node_allocator>::value&& is_nothrow_move_constructible<value_compare>::value);
+  _LIBCPP_HIDE_FROM_ABI __tree(__tree&& __t, const allocator_type& __a);
+
+  _LIBCPP_HIDE_FROM_ABI __tree& operator=(__tree&& __t)
+      _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
+                 ((__node_traits::propagate_on_container_move_assignment::value &&
+                   is_nothrow_move_assignable<__node_allocator>::value) ||
+                  allocator_traits<__node_allocator>::is_always_equal::value)) {
+    __move_assign(__t,
+                  integral_constant<bool,
+                                    __node_traits::propagate_on_container_move_assignment::value ||
+                                        __node_traits::is_always_equal::value>());
+    return *this;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI ~__tree() {
+    static_assert(is_copy_constructible<value_compare>::value, "Comparator must be copy-constructible.");
+    destroy(__root());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return iterator(__begin_node_); }
+  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return const_iterator(__begin_node_); }
+  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return iterator(__end_node()); }
+  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return const_iterator(__end_node()); }
+
+  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
+    return std::min<size_type>(__node_traits::max_size(__node_alloc()), numeric_limits<difference_type >::max());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT;
+
+  _LIBCPP_HIDE_FROM_ABI void swap(__tree& __t)
+#if _LIBCPP_STD_VER <= 11
+      _NOEXCEPT_(__is_nothrow_swappable_v<value_compare> &&
+                 (!__node_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__node_allocator>));
+#else
+      _NOEXCEPT_(__is_nothrow_swappable_v<value_compare>);
+#endif
+
+  template <class... _Args>
+  _LIBCPP_HIDE_FROM_ABI iterator __emplace_multi(_Args&&... __args);
+
+  template <class... _Args>
+  _LIBCPP_HIDE_FROM_ABI iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
+
+  template <class... _Args>
+  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> __emplace_unique(_Args&&... __args) {
+    return std::__try_key_extraction<key_type>(
+        [this](const key_type& __key, _Args&&... __args2) {
+          auto [__parent, __child] = __find_equal(__key);
+          __node_pointer __r       = std::__static_fancy_pointer_cast<__node_pointer>(__child);
+          bool __inserted          = false;
+          if (__child == nullptr) {
+            __node_holder __h = __construct_node(std::forward<_Args>(__args2)...);
+            __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__h.get()));
+            __r        = __h.release();
+            __inserted = true;
+          }
+          return pair<iterator, bool>(iterator(__r), __inserted);
+        },
+        [this](_Args&&... __args2) {
+          __node_holder __h        = __construct_node(std::forward<_Args>(__args2)...);
+          auto [__parent, __child] = __find_equal(__h->__get_value());
+          __node_pointer __r       = std::__static_fancy_pointer_cast<__node_pointer>(__child);
+          bool __inserted          = false;
+          if (__child == nullptr) {
+            __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__h.get()));
+            __r        = __h.release();
+            __inserted = true;
+          }
+          return pair<iterator, bool>(iterator(__r), __inserted);
+        },
+        std::forward<_Args>(__args)...);
+  }
+
+  template <class... _Args>
+  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> __emplace_hint_unique(const_iterator __p, _Args&&... __args) {
+    return std::__try_key_extraction<key_type>(
+        [this, __p](const key_type& __key, _Args&&... __args2) {
+          __node_base_pointer __dummy;
+          auto [__parent, __child] = __find_equal(__p, __dummy, __key);
+          __node_pointer __r       = std::__static_fancy_pointer_cast<__node_pointer>(__child);
+          bool __inserted          = false;
+          if (__child == nullptr) {
+            __node_holder __h = __construct_node(std::forward<_Args>(__args2)...);
+            __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__h.get()));
+            __r        = __h.release();
+            __inserted = true;
+          }
+          return pair<iterator, bool>(iterator(__r), __inserted);
+        },
+        [this, __p](_Args&&... __args2) {
+          __node_holder __h = __construct_node(std::forward<_Args>(__args2)...);
+          __node_base_pointer __dummy;
+          auto [__parent, __child] = __find_equal(__p, __dummy, __h->__get_value());
+          __node_pointer __r       = std::__static_fancy_pointer_cast<__node_pointer>(__child);
+          if (__child == nullptr) {
+            __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__h.get()));
+            __r = __h.release();
+          }
+          return pair<iterator, bool>(iterator(__r), __child == nullptr);
+        },
+        std::forward<_Args>(__args)...);
+  }
+
+  template <class _InIter, class _Sent>
+  _LIBCPP_HIDE_FROM_ABI void __insert_range_multi(_InIter __first, _Sent __last) {
+    if (__first == __last)
+      return;
+
+    if (__root() == nullptr) { // Make sure we always have a root node
+      __insert_node_at(__end_node(),
+                       __end_node()->__left_,
+                       std::__static_fancy_pointer_cast<__node_base_pointer>(__construct_node(*__first).release()));
+      ++__first;
+    }
+
+    auto __max_node = std::__static_fancy_pointer_cast<__node_pointer>(
+        std::__tree_max(std::__static_fancy_pointer_cast<__node_base_pointer>(__root())));
+
+    for (; __first != __last; ++__first) {
+      __node_holder __nd = __construct_node(*__first);
+      // Always check the max node first. This optimizes for sorted ranges inserted at the end.
+      if (!value_comp()(__nd->__get_value(), __max_node->__get_value())) { // __node >= __max_val
+        __insert_node_at(std::__static_fancy_pointer_cast<__end_node_pointer>(__max_node),
+                         __max_node->__right_,
+                         std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.get()));
+        __max_node = __nd.release();
+      } else {
+        __end_node_pointer __parent;
+        __node_base_pointer& __child = __find_leaf_high(__parent, __nd->__get_value());
+        __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.release()));
+      }
+    }
+  }
+
+  template <class _InIter, class _Sent>
+  _LIBCPP_HIDE_FROM_ABI void __insert_range_unique(_InIter __first, _Sent __last) {
+    if (__first == __last)
+      return;
+
+    if (__root() == nullptr) {
+      __insert_node_at(__end_node(),
+                       __end_node()->__left_,
+                       std::__static_fancy_pointer_cast<__node_base_pointer>(__construct_node(*__first).release()));
+      ++__first;
+    }
+
+    auto __max_node = std::__static_fancy_pointer_cast<__node_pointer>(
+        std::__tree_max(std::__static_fancy_pointer_cast<__node_base_pointer>(__root())));
+
+    using __reference = decltype(*__first);
+
+    for (; __first != __last; ++__first) {
+      std::__try_key_extraction<key_type>(
+          [this, &__max_node](const key_type& __key, __reference&& __val) {
+            if (value_comp()(__max_node->__get_value(), __key)) { // __key > __max_node
+              __node_holder __nd = __construct_node(std::forward<__reference>(__val));
+              __insert_node_at(std::__static_fancy_pointer_cast<__end_node_pointer>(__max_node),
+                               __max_node->__right_,
+                               std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.get()));
+              __max_node = __nd.release();
+            } else {
+              auto [__parent, __child] = __find_equal(__key);
+              if (__child == nullptr) {
+                __node_holder __nd = __construct_node(std::forward<__reference>(__val));
+                __insert_node_at(
+                    __parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.release()));
+              }
+            }
+          },
+          [this, &__max_node](__reference&& __val) {
+            __node_holder __nd = __construct_node(std::forward<__reference>(__val));
+            if (value_comp()(__max_node->__get_value(), __nd->__get_value())) { // __node > __max_node
+              __insert_node_at(std::__static_fancy_pointer_cast<__end_node_pointer>(__max_node),
+                               __max_node->__right_,
+                               std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.get()));
+              __max_node = __nd.release();
+            } else {
+              auto [__parent, __child] = __find_equal(__nd->__get_value());
+              if (__child == nullptr) {
+                __insert_node_at(
+                    __parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__nd.release()));
+              }
+            }
+          },
+          *__first);
+    }
+  }
+
+  _LIBCPP_HIDE_FROM_ABI iterator __remove_node_pointer(__node_pointer) _NOEXCEPT;
+
+#if _LIBCPP_STD_VER >= 17
+  template <class _NodeHandle, class _InsertReturnType>
+  _LIBCPP_HIDE_FROM_ABI _InsertReturnType __node_handle_insert_unique(_NodeHandle&&);
+  template <class _NodeHandle>
+  _LIBCPP_HIDE_FROM_ABI iterator __node_handle_insert_unique(const_iterator, _NodeHandle&&);
+  template <class _Comp2>
+  _LIBCPP_HIDE_FROM_ABI void __node_handle_merge_unique(__tree<_Tp, _Comp2, _Allocator>& __source);
+
+  template <class _NodeHandle>
+  _LIBCPP_HIDE_FROM_ABI iterator __node_handle_insert_multi(_NodeHandle&&);
+  template <class _NodeHandle>
+  _LIBCPP_HIDE_FROM_ABI iterator __node_handle_insert_multi(const_iterator, _NodeHandle&&);
+  template <class _Comp2>
+  _LIBCPP_HIDE_FROM_ABI void __node_handle_merge_multi(__tree<_Tp, _Comp2, _Allocator>& __source);
+
+  template <class _NodeHandle>
+  _LIBCPP_HIDE_FROM_ABI _NodeHandle __node_handle_extract(key_type const&);
+  template <class _NodeHandle>
+  _LIBCPP_HIDE_FROM_ABI _NodeHandle __node_handle_extract(const_iterator);
+#endif
+
+  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p);
+  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __f, const_iterator __l);
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI size_type __erase_unique(const _Key& __k);
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI size_type __erase_multi(const _Key& __k);
+
+  _LIBCPP_HIDE_FROM_ABI void
+  __insert_node_at(__end_node_pointer __parent, __node_base_pointer& __child, __node_base_pointer __new_node) _NOEXCEPT;
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator find(const _Key& __key) {
+    auto [__, __match] = __find_equal(__key);
+    if (__match == nullptr)
+      return end();
+    return iterator(std::__static_fancy_pointer_cast<__node_pointer>(__match));
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _Key& __key) const {
+    auto [__, __match] = __find_equal(__key);
+    if (__match == nullptr)
+      return end();
+    return const_iterator(std::__static_fancy_pointer_cast<__node_pointer>(__match));
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI size_type __count_unique(const _Key& __k) const;
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI size_type __count_multi(const _Key& __k) const;
+
+  template <bool _LowerBound, class _Key>
+  _LIBCPP_HIDE_FROM_ABI __end_node_pointer __lower_upper_bound_unique_impl(const _Key& __v) const {
+    auto __rt     = __root();
+    auto __result = __end_node();
+    auto __comp   = __lazy_synth_three_way_comparator<_Compare, _Key, value_type>(value_comp());
+    while (__rt != nullptr) {
+      auto __comp_res = __comp(__v, __rt->__get_value());
+
+      if (__comp_res.__less()) {
+        __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+        __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+      } else if (__comp_res.__greater()) {
+        __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+      } else if _LIBCPP_CONSTEXPR (_LowerBound) {
+        return std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+      } else {
+        return __rt->__right_ ? std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__rt->__right_))
+                              : __result;
+      }
+    }
+    return __result;
+  }
+
+  // Compatibility escape hatch for comparators that are not strict weak orderings. This
+  // can be removed for the LLVM 23 release.
+#if defined(_LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND)
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI __end_node_pointer __lower_bound_unique_compat_impl(const _Key& __v) const {
+    auto __rt     = __root();
+    auto __result = __end_node();
+    while (__rt != nullptr) {
+      if (!value_comp()(__rt->__get_value(), __v)) {
+        __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+        __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+      } else {
+        __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+      }
+    }
+    return __result;
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI __end_node_pointer __upper_bound_unique_compat_impl(const _Key& __v) const {
+    auto __rt     = __root();
+    auto __result = __end_node();
+    while (__rt != nullptr) {
+      if (value_comp()(__v, __rt->__get_value())) {
+        __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+        __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+      } else {
+        __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+      }
+    }
+    return __result;
+  }
+#endif // _LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator __lower_bound_unique(const _Key& __v) {
+#if defined(_LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND)
+    return iterator(__lower_bound_unique_compat_impl(__v));
+#else
+    return iterator(__lower_upper_bound_unique_impl<true>(__v));
+#endif
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator __lower_bound_unique(const _Key& __v) const {
+#if defined(_LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND)
+    return const_iterator(__lower_bound_unique_compat_impl(__v));
+#else
+    return const_iterator(__lower_upper_bound_unique_impl<true>(__v));
+#endif
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator __upper_bound_unique(const _Key& __v) {
+#if defined(_LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND)
+    return iterator(__upper_bound_unique_compat_impl(__v));
+#else
+    return iterator(__lower_upper_bound_unique_impl<false>(__v));
+#endif
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator __upper_bound_unique(const _Key& __v) const {
+#if defined(_LIBCPP_ENABLE_LEGACY_TREE_LOWER_UPPER_BOUND)
+    return iterator(__upper_bound_unique_compat_impl(__v));
+#else
+    return iterator(__lower_upper_bound_unique_impl<false>(__v));
+#endif
+  }
+
+private:
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator
+  __lower_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator
+  __lower_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+
+public:
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator __lower_bound_multi(const _Key& __v) {
+    return __lower_bound_multi(__v, __root(), __end_node());
+  }
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator __lower_bound_multi(const _Key& __v) const {
+    return __lower_bound_multi(__v, __root(), __end_node());
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator __upper_bound_multi(const _Key& __v) {
+    return __upper_bound_multi(__v, __root(), __end_node());
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator __upper_bound_multi(const _Key& __v) const {
+    return __upper_bound_multi(__v, __root(), __end_node());
+  }
+
+private:
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI iterator
+  __upper_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI const_iterator
+  __upper_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+
+public:
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> __equal_range_unique(const _Key& __k);
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> __equal_range_unique(const _Key& __k) const;
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> __equal_range_multi(const _Key& __k);
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> __equal_range_multi(const _Key& __k) const;
+
+  using _Dp _LIBCPP_NODEBUG           = __tree_node_destructor<__node_allocator>;
+  using __node_holder _LIBCPP_NODEBUG = unique_ptr<__node, _Dp>;
+
+  _LIBCPP_HIDE_FROM_ABI __node_holder remove(const_iterator __p) _NOEXCEPT;
+
+  // FIXME: Make this function const qualified. Unfortunately doing so
+  // breaks existing code which uses non-const callable comparators.
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<__end_node_pointer, __node_base_pointer&> __find_equal(const _Key& __v);
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<__end_node_pointer, __node_base_pointer&> __find_equal(const _Key& __v) const {
+    return const_cast<__tree*>(this)->__find_equal(__v);
+  }
+
+  template <class _Key>
+  _LIBCPP_HIDE_FROM_ABI pair<__end_node_pointer, __node_base_pointer&>
+  __find_equal(const_iterator __hint, __node_base_pointer& __dummy, const _Key& __v);
+
+  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const __tree& __t) {
+    __copy_assign_alloc(__t, integral_constant<bool, __node_traits::propagate_on_container_copy_assignment::value>());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const __tree& __t, true_type) {
+    if (__node_alloc() != __t.__node_alloc())
+      clear();
+    __node_alloc() = __t.__node_alloc();
+  }
+  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const __tree&, false_type) {}
+
+private:
+  _LIBCPP_HIDE_FROM_ABI __node_base_pointer& __find_leaf_low(__end_node_pointer& __parent, const value_type& __v);
+
+  _LIBCPP_HIDE_FROM_ABI __node_base_pointer& __find_leaf_high(__end_node_pointer& __parent, const value_type& __v);
+
+  _LIBCPP_HIDE_FROM_ABI __node_base_pointer&
+  __find_leaf(const_iterator __hint, __end_node_pointer& __parent, const value_type& __v);
+
+  template <class... _Args>
+  _LIBCPP_HIDE_FROM_ABI __node_holder __construct_node(_Args&&... __args);
+
+  // TODO: Make this _LIBCPP_HIDE_FROM_ABI
+  _LIBCPP_HIDDEN void destroy(__node_pointer __nd) _NOEXCEPT { (__tree_deleter(__node_alloc_))(__nd); }
+
+  _LIBCPP_HIDE_FROM_ABI void __move_assign(__tree& __t, false_type);
+  _LIBCPP_HIDE_FROM_ABI void __move_assign(__tree& __t, true_type) _NOEXCEPT_(
+      is_nothrow_move_assignable<value_compare>::value&& is_nothrow_move_assignable<__node_allocator>::value);
+
+  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__tree& __t)
+      _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value ||
+                 is_nothrow_move_assignable<__node_allocator>::value) {
+    __move_assign_alloc(__t, integral_constant<bool, __node_traits::propagate_on_container_move_assignment::value>());
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__tree& __t, true_type)
+      _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value) {
+    __node_alloc() = std::move(__t.__node_alloc());
+  }
+  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {}
+
+  template <class _From, class _ValueT = _Tp, __enable_if_t<__is_tree_value_type_v<_ValueT>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI static void __assign_value(__get_node_value_type_t<value_type>& __lhs, _From&& __rhs) {
+    using __key_type = __remove_const_t<typename value_type::first_type>;
+
+    // This is technically UB, since the object was constructed as `const`.
+    // Clang doesn't optimize on this currently though.
+    const_cast<__key_type&>(__lhs.first) = const_cast<__copy_cvref_t<_From, __key_type>&&>(__rhs.first);
+    __lhs.second                         = std::forward<_From>(__rhs).second;
+  }
+
+  template <class _To, class _From, class _ValueT = _Tp, __enable_if_t<!__is_tree_value_type_v<_ValueT>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI static void __assign_value(_To& __lhs, _From&& __rhs) {
+    __lhs = std::forward<_From>(__rhs);
+  }
+
+  class __tree_deleter {
+    __node_allocator& __alloc_;
+
+  public:
+    using pointer = __node_pointer;
+
+    _LIBCPP_HIDE_FROM_ABI __tree_deleter(__node_allocator& __alloc) : __alloc_(__alloc) {}
+
+#ifdef _LIBCPP_COMPILER_CLANG_BASED // FIXME: GCC complains about not being able to always_inline a recursive function
+    _LIBCPP_HIDE_FROM_ABI
+#endif
+    void
+    operator()(__node_pointer __ptr) {
+      if (!__ptr)
+        return;
+
+      (*this)(std::__static_fancy_pointer_cast<__node_pointer>(__ptr->__left_));
+
+      auto __right = __ptr->__right_;
+
+      __node_traits::destroy(__alloc_, std::addressof(__ptr->__get_value()));
+      __node_traits::deallocate(__alloc_, __ptr, 1);
+
+      (*this)(std::__static_fancy_pointer_cast<__node_pointer>(__right));
+    }
+  };
+
+  // This copy construction will always produce a correct red-black-tree assuming the incoming tree is correct, since we
+  // copy the exact structure 1:1. Since this is for copy construction _only_ we know that we get a correct tree. If we
+  // didn't get a correct tree, the invariants of __tree are broken and we have a much bigger problem than an improperly
+  // balanced tree.
+  template <class _NodeConstructor>
+#ifdef _LIBCPP_COMPILER_CLANG_BASED // FIXME: GCC complains about not being able to always_inline a recursive function
+  _LIBCPP_HIDE_FROM_ABI
+#endif
+  __node_pointer __construct_from_tree(__node_pointer __src, _NodeConstructor __construct) {
+    if (!__src)
+      return nullptr;
+
+    __node_holder __new_node = __construct(__src->__get_value());
+
+    unique_ptr<__node, __tree_deleter> __left(
+        __construct_from_tree(std::__static_fancy_pointer_cast<__node_pointer>(__src->__left_), __construct),
+        __node_alloc_);
+    __node_pointer __right =
+        __construct_from_tree(std::__static_fancy_pointer_cast<__node_pointer>(__src->__right_), __construct);
+
+    __node_pointer __new_node_ptr = __new_node.release();
+
+    __new_node_ptr->__is_black_ = __src->__is_black_;
+    __new_node_ptr->__left_     = std::__static_fancy_pointer_cast<__node_base_pointer>(__left.release());
+    __new_node_ptr->__right_    = std::__static_fancy_pointer_cast<__node_base_pointer>(__right);
+    if (__new_node_ptr->__left_)
+      __new_node_ptr->__left_->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__new_node_ptr);
+    if (__new_node_ptr->__right_)
+      __new_node_ptr->__right_->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__new_node_ptr);
+    return __new_node_ptr;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __copy_construct_tree(__node_pointer __src) {
+    return __construct_from_tree(__src, [this](const value_type& __val) { return __construct_node(__val); });
+  }
+
+  template <class _ValueT = _Tp, __enable_if_t<__is_tree_value_type_v<_ValueT>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __move_construct_tree(__node_pointer __src) {
+    return __construct_from_tree(__src, [this](value_type& __val) {
+      return __construct_node(const_cast<key_type&&>(__val.first), std::move(__val.second));
+    });
+  }
+
+  template <class _ValueT = _Tp, __enable_if_t<!__is_tree_value_type_v<_ValueT>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __move_construct_tree(__node_pointer __src) {
+    return __construct_from_tree(__src, [this](value_type& __val) { return __construct_node(std::move(__val)); });
+  }
+
+  template <class _Assignment, class _ConstructionAlg>
+  // This copy assignment will always produce a correct red-black-tree assuming the incoming tree is correct, since our
+  // own tree is a red-black-tree and the incoming tree is a red-black-tree. The invariants of a red-black-tree are
+  // temporarily not met until all of the incoming red-black tree is copied.
+#ifdef _LIBCPP_COMPILER_CLANG_BASED // FIXME: GCC complains about not being able to always_inline a recursive function
+  _LIBCPP_HIDE_FROM_ABI
+#endif
+  __node_pointer __assign_from_tree(
+      __node_pointer __dest, __node_pointer __src, _Assignment __assign, _ConstructionAlg __construct_subtree) {
+    if (!__src) {
+      destroy(__dest);
+      return nullptr;
+    }
+
+    __assign(__dest->__get_value(), __src->__get_value());
+    __dest->__is_black_ = __src->__is_black_;
+
+    // If we already have a left node in the destination tree, reuse it and copy-assign recursively
+    if (__dest->__left_) {
+      __dest->__left_ = std::__static_fancy_pointer_cast<__node_base_pointer>(__assign_from_tree(
+          std::__static_fancy_pointer_cast<__node_pointer>(__dest->__left_),
+          std::__static_fancy_pointer_cast<__node_pointer>(__src->__left_),
+          __assign,
+          __construct_subtree));
+
+      // Otherwise, we must create new nodes; copy-construct from here on
+    } else if (__src->__left_) {
+      auto __new_left       = __construct_subtree(std::__static_fancy_pointer_cast<__node_pointer>(__src->__left_));
+      __dest->__left_       = std::__static_fancy_pointer_cast<__node_base_pointer>(__new_left);
+      __new_left->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__dest);
+    }
+
+    // Identical to the left case above, just for the right nodes
+    if (__dest->__right_) {
+      __dest->__right_ = std::__static_fancy_pointer_cast<__node_base_pointer>(__assign_from_tree(
+          std::__static_fancy_pointer_cast<__node_pointer>(__dest->__right_),
+          std::__static_fancy_pointer_cast<__node_pointer>(__src->__right_),
+          __assign,
+          __construct_subtree));
+    } else if (__src->__right_) {
+      auto __new_right       = __construct_subtree(std::__static_fancy_pointer_cast<__node_pointer>(__src->__right_));
+      __dest->__right_       = std::__static_fancy_pointer_cast<__node_base_pointer>(__new_right);
+      __new_right->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__dest);
+    }
+
+    return __dest;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __copy_assign_tree(__node_pointer __dest, __node_pointer __src) {
+    return __assign_from_tree(
+        __dest,
+        __src,
+        [](value_type& __lhs, const value_type& __rhs) { __assign_value(__lhs, __rhs); },
+        [this](__node_pointer __nd) { return __copy_construct_tree(__nd); });
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __node_pointer __move_assign_tree(__node_pointer __dest, __node_pointer __src) {
+    return __assign_from_tree(
+        __dest,
+        __src,
+        [](value_type& __lhs, value_type& __rhs) { __assign_value(__lhs, std::move(__rhs)); },
+        [this](__node_pointer __nd) { return __move_construct_tree(__nd); });
+  }
+
+  friend struct __specialized_algorithm<_Algorithm::__for_each, __single_range<__tree> >;
+};
+
+#if _LIBCPP_STD_VER >= 14
+template <class _Tp, class _Compare, class _Allocator>
+struct __specialized_algorithm<_Algorithm::__for_each, __single_range<__tree<_Tp, _Compare, _Allocator> > > {
+  static const bool __has_algorithm = true;
+
+  using __node_pointer _LIBCPP_NODEBUG = typename __tree<_Tp, _Compare, _Allocator>::__node_pointer;
+
+  template <class _Tree, class _Func, class _Proj>
+  _LIBCPP_HIDE_FROM_ABI static auto operator()(_Tree&& __range, _Func __func, _Proj __proj) {
+    if (__range.size() != 0)
+      std::__tree_iterate_from_root<__copy_cvref_t<_Tree, typename __remove_cvref_t<_Tree>::value_type>>(
+          [](__node_pointer) { return false; }, __range.__root(), __func, __proj);
+    return std::make_pair(__range.end(), std::move(__func));
+  }
+};
+#endif
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>& __tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t) {
+  if (this == std::addressof(__t))
+    return *this;
+
+  value_comp() = __t.value_comp();
+  __copy_assign_alloc(__t);
+
+  if (__size_ != 0) {
+    *__root_ptr() = std::__static_fancy_pointer_cast<__node_base_pointer>(__copy_assign_tree(__root(), __t.__root()));
+  } else {
+    *__root_ptr() = std::__static_fancy_pointer_cast<__node_base_pointer>(__copy_construct_tree(__t.__root()));
+    if (__root())
+      __root()->__parent_ = __end_node();
+  }
+  __begin_node_ = __end_node()->__left_
+                    ? std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__end_node()->__left_))
+                    : __end_node();
+  __size_ = __t.size();
+
+  return *this;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
+    : __begin_node_(__end_node()),
+      __node_alloc_(__node_traits::select_on_container_copy_construction(__t.__node_alloc())),
+      __size_(0),
+      __value_comp_(__t.value_comp()) {
+  if (__t.size() == 0)
+    return;
+
+  *__root_ptr()       = std::__static_fancy_pointer_cast<__node_base_pointer>(__copy_construct_tree(__t.__root()));
+  __root()->__parent_ = __end_node();
+  __begin_node_       = std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__end_node()->__left_));
+  __size_             = __t.size();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t) _NOEXCEPT_(
+    is_nothrow_move_constructible<__node_allocator>::value&& is_nothrow_move_constructible<value_compare>::value)
+    : __begin_node_(std::move(__t.__begin_node_)),
+      __end_node_(std::move(__t.__end_node_)),
+      __node_alloc_(std::move(__t.__node_alloc_)),
+      __size_(__t.__size_),
+      __value_comp_(std::move(__t.__value_comp_)) {
+  if (__size_ == 0)
+    __begin_node_ = __end_node();
+  else {
+    __end_node()->__left_->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__end_node());
+    __t.__begin_node_                = __t.__end_node();
+    __t.__end_node()->__left_        = nullptr;
+    __t.__size_                      = 0;
+  }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a)
+    : __begin_node_(__end_node()),
+      __node_alloc_(__node_allocator(__a)),
+      __size_(0),
+      __value_comp_(std::move(__t.value_comp())) {
+  if (__t.size() == 0)
+    return;
+  if (__a == __t.__alloc()) {
+    __begin_node_                    = __t.__begin_node_;
+    __end_node()->__left_            = __t.__end_node()->__left_;
+    __end_node()->__left_->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__end_node());
+    __size_                          = __t.__size_;
+    __t.__begin_node_                = __t.__end_node();
+    __t.__end_node()->__left_        = nullptr;
+    __t.__size_                      = 0;
+  } else {
+    *__root_ptr()       = std::__static_fancy_pointer_cast<__node_base_pointer>(__move_construct_tree(__t.__root()));
+    __root()->__parent_ = __end_node();
+    __begin_node_       = std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__end_node()->__left_));
+    __size_             = __t.size();
+    __t.clear(); // Ensure that __t is in a valid state after moving out the keys
+  }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void __tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
+    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value&& is_nothrow_move_assignable<__node_allocator>::value) {
+  destroy(std::__static_fancy_pointer_cast<__node_pointer>(__end_node()->__left_));
+  __begin_node_ = __t.__begin_node_;
+  __end_node_   = __t.__end_node_;
+  __move_assign_alloc(__t);
+  __size_       = __t.__size_;
+  __value_comp_ = std::move(__t.__value_comp_);
+  if (__size_ == 0)
+    __begin_node_ = __end_node();
+  else {
+    __end_node()->__left_->__parent_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__end_node());
+    __t.__begin_node_                = __t.__end_node();
+    __t.__end_node()->__left_        = nullptr;
+    __t.__size_                      = 0;
+  }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void __tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type) {
+  if (__node_alloc() == __t.__node_alloc()) {
+    __move_assign(__t, true_type());
+  } else {
+    value_comp() = std::move(__t.value_comp());
+    if (__size_ != 0) {
+      *__root_ptr() = std::__static_fancy_pointer_cast<__node_base_pointer>(__move_assign_tree(__root(), __t.__root()));
+    } else {
+      *__root_ptr() = std::__static_fancy_pointer_cast<__node_base_pointer>(__move_construct_tree(__t.__root()));
+      if (__root())
+        __root()->__parent_ = __end_node();
+    }
+    __begin_node_ = __end_node()->__left_
+                      ? std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__end_node()->__left_))
+                      : __end_node();
+    __size_ = __t.size();
+    __t.clear(); // Ensure that __t is in a valid state after moving out the keys
+  }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void __tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
+#if _LIBCPP_STD_VER <= 11
+    _NOEXCEPT_(__is_nothrow_swappable_v<value_compare> &&
+               (!__node_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__node_allocator>))
+#else
+    _NOEXCEPT_(__is_nothrow_swappable_v<value_compare>)
+#endif
+{
+  using std::swap;
+  swap(__begin_node_, __t.__begin_node_);
+  swap(__end_node_, __t.__end_node_);
+  std::__swap_allocator(__node_alloc(), __t.__node_alloc());
+  swap(__size_, __t.__size_);
+  swap(__value_comp_, __t.__value_comp_);
+  if (__size_ == 0)
+    __begin_node_ = __end_node();
+  else
+    __end_node()->__left_->__parent_ = __end_node();
+  if (__t.__size_ == 0)
+    __t.__begin_node_ = __t.__end_node();
+  else
+    __t.__end_node()->__left_->__parent_ = __t.__end_node();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void __tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT {
+  destroy(__root());
+  __size_               = 0;
+  __begin_node_         = __end_node();
+  __end_node()->__left_ = nullptr;
+}
+
+// Find lower_bound place to insert
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__end_node_pointer& __parent, const value_type& __v) {
+  __node_pointer __nd = __root();
+  if (__nd != nullptr) {
+    while (true) {
+      if (value_comp()(__nd->__get_value(), __v)) {
+        if (__nd->__right_ != nullptr)
+          __nd = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__right_);
+        else {
+          __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__nd);
+          return __nd->__right_;
+        }
+      } else {
+        if (__nd->__left_ != nullptr)
+          __nd = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__left_);
+        else {
+          __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__nd);
+          return __parent->__left_;
+        }
+      }
+    }
+  }
+  __parent = __end_node();
+  return __parent->__left_;
+}
+
+// Find upper_bound place to insert
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__end_node_pointer& __parent, const value_type& __v) {
+  __node_pointer __nd = __root();
+  if (__nd != nullptr) {
+    while (true) {
+      if (value_comp()(__v, __nd->__get_value())) {
+        if (__nd->__left_ != nullptr)
+          __nd = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__left_);
+        else {
+          __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__nd);
+          return __parent->__left_;
+        }
+      } else {
+        if (__nd->__right_ != nullptr)
+          __nd = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__right_);
+        else {
+          __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__nd);
+          return __nd->__right_;
+        }
+      }
+    }
+  }
+  __parent = __end_node();
+  return __parent->__left_;
+}
+
+// Find leaf place to insert closest to __hint
+// First check prior to __hint.
+// Next check after __hint.
+// Next do O(log N) search.
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& __tree<_Tp, _Compare, _Allocator>::__find_leaf(
+    const_iterator __hint, __end_node_pointer& __parent, const value_type& __v) {
+  if (__hint == end() || !value_comp()(*__hint, __v)) // check before
+  {
+    // __v <= *__hint
+    const_iterator __prior = __hint;
+    if (__prior == begin() || !value_comp()(__v, *--__prior)) {
+      // *prev(__hint) <= __v <= *__hint
+      if (__hint.__ptr_->__left_ == nullptr) {
+        __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__hint.__ptr_);
+        return __parent->__left_;
+      } else {
+        __parent = std::__static_fancy_pointer_cast<__end_node_pointer>(__prior.__ptr_);
+        return std::__static_fancy_pointer_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
+      }
+    }
+    // __v < *prev(__hint)
+    return __find_leaf_high(__parent, __v);
+  }
+  // else __v > *__hint
+  return __find_leaf_low(__parent, __v);
+}
+
+// Find __v
+// If __v exists, return the parent of the node of __v and a reference to the pointer to the node of __v.
+// If __v doesn't exist, return the parent of the null leaf and a reference to the pointer to the null leaf.
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+_LIBCPP_HIDE_FROM_ABI pair<typename __tree<_Tp, _Compare, _Allocator>::__end_node_pointer,
+                           typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&>
+__tree<_Tp, _Compare, _Allocator>::__find_equal(const _Key& __v) {
+  using _Pair = pair<__end_node_pointer, __node_base_pointer&>;
+
+  __node_pointer __nd = __root();
+
+  if (__nd == nullptr) {
+    auto __end = __end_node();
+    return _Pair(__end, __end->__left_);
+  }
+
+  __node_base_pointer* __node_ptr = __root_ptr();
+  auto&& __transparent            = std::__as_transparent<key_type>(value_comp());
+  auto __comp =
+      __lazy_synth_three_way_comparator<__make_transparent_t<key_type, _Compare>, _Key, value_type>(__transparent);
+
+  while (true) {
+    auto __comp_res = __comp(__v, __nd->__get_value());
+
+    if (__comp_res.__less()) {
+      if (__nd->__left_ == nullptr)
+        return _Pair(std::__static_fancy_pointer_cast<__end_node_pointer>(__nd), __nd->__left_);
+
+      __node_ptr = std::addressof(__nd->__left_);
+      __nd       = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__left_);
+    } else if (__comp_res.__greater()) {
+      if (__nd->__right_ == nullptr)
+        return _Pair(std::__static_fancy_pointer_cast<__end_node_pointer>(__nd), __nd->__right_);
+
+      __node_ptr = std::addressof(__nd->__right_);
+      __nd       = std::__static_fancy_pointer_cast<__node_pointer>(__nd->__right_);
+    } else {
+      return _Pair(std::__static_fancy_pointer_cast<__end_node_pointer>(__nd), *__node_ptr);
+    }
+  }
+}
+
+// Find __v
+// First check prior to __hint.
+// Next check after __hint.
+// Next do O(log N) search.
+// If __v exists, return the parent of the node of __v and a reference to the pointer to the node of __v.
+// If __v doesn't exist, return the parent of the null leaf and a reference to the pointer to the null leaf.
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+_LIBCPP_HIDE_FROM_ABI pair<typename __tree<_Tp, _Compare, _Allocator>::__end_node_pointer,
+                           typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&>
+__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint, __node_base_pointer& __dummy, const _Key& __v) {
+  using _Pair = pair<__end_node_pointer, __node_base_pointer&>;
+
+  if (__hint == end() || value_comp()(__v, *__hint)) { // check before
+    // __v < *__hint
+    const_iterator __prior = __hint;
+    if (__prior == begin() || value_comp()(*--__prior, __v)) {
+      // *prev(__hint) < __v < *__hint
+      if (__hint.__ptr_->__left_ == nullptr)
+        return _Pair(__hint.__ptr_, __hint.__ptr_->__left_);
+      return _Pair(__prior.__ptr_, std::__static_fancy_pointer_cast<__node_pointer>(__prior.__ptr_)->__right_);
+    }
+    // __v <= *prev(__hint)
+    return __find_equal(__v);
+  }
+
+  if (value_comp()(*__hint, __v)) { // check after
+    // *__hint < __v
+    const_iterator __next = std::next(__hint);
+    if (__next == end() || value_comp()(__v, *__next)) {
+      // *__hint < __v < *std::next(__hint)
+      if (__hint.__get_np()->__right_ == nullptr)
+        return _Pair(__hint.__ptr_, std::__static_fancy_pointer_cast<__node_pointer>(__hint.__ptr_)->__right_);
+      return _Pair(__next.__ptr_, __next.__ptr_->__left_);
+    }
+    // *next(__hint) <= __v
+    return __find_equal(__v);
+  }
+
+  // else __v == *__hint
+  __dummy = static_cast<__node_base_pointer>(__hint.__ptr_);
+  return _Pair(__hint.__ptr_, __dummy);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void __tree<_Tp, _Compare, _Allocator>::__insert_node_at(
+    __end_node_pointer __parent, __node_base_pointer& __child, __node_base_pointer __new_node) _NOEXCEPT {
+  __new_node->__left_   = nullptr;
+  __new_node->__right_  = nullptr;
+  __new_node->__parent_ = __parent;
+  // __new_node->__is_black_ is initialized in __tree_balance_after_insert
+  __child = __new_node;
+  if (__begin_node_->__left_ != nullptr)
+    __begin_node_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__begin_node_->__left_);
+  std::__tree_balance_after_insert(__end_node()->__left_, __child);
+  ++__size_;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder
+__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&&... __args) {
+  __node_allocator& __na = __node_alloc();
+  __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+  std::__construct_at(std::addressof(*__h), __na, std::forward<_Args>(__args)...);
+  __h.get_deleter().__value_constructed = true;
+  return __h;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args) {
+  __node_holder __h = __construct_node(std::forward<_Args>(__args)...);
+  __end_node_pointer __parent;
+  __node_base_pointer& __child = __find_leaf_high(__parent, __h->__get_value());
+  __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+  return iterator(static_cast<__node_pointer>(__h.release()));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p, _Args&&... __args) {
+  __node_holder __h = __construct_node(std::forward<_Args>(__args)...);
+  __end_node_pointer __parent;
+  __node_base_pointer& __child = __find_leaf(__p, __parent, __h->__get_value());
+  __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+  return iterator(static_cast<__node_pointer>(__h.release()));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__remove_node_pointer(__node_pointer __ptr) _NOEXCEPT {
+  iterator __r(__ptr);
+  ++__r;
+  if (__begin_node_ == __ptr)
+    __begin_node_ = __r.__ptr_;
+  --__size_;
+  std::__tree_remove(__end_node()->__left_, static_cast<__node_base_pointer>(__ptr));
+  return __r;
+}
+
+#if _LIBCPP_STD_VER >= 17
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle, class _InsertReturnType>
+_LIBCPP_HIDE_FROM_ABI _InsertReturnType
+__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(_NodeHandle&& __nh) {
+  if (__nh.empty())
+    return _InsertReturnType{end(), false, _NodeHandle()};
+
+  __node_pointer __ptr = __nh.__ptr_;
+  auto [__parent, __child] = __find_equal(__ptr->__get_value());
+  if (__child != nullptr)
+    return _InsertReturnType{iterator(static_cast<__node_pointer>(__child)), false, std::move(__nh)};
+
+  __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
+  __nh.__release_ptr();
+  return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle>
+_LIBCPP_HIDE_FROM_ABI typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(const_iterator __hint, _NodeHandle&& __nh) {
+  if (__nh.empty())
+    return end();
+
+  __node_pointer __ptr = __nh.__ptr_;
+  __node_base_pointer __dummy;
+  auto [__parent, __child] = __find_equal(__hint, __dummy, __ptr->__get_value());
+  __node_pointer __r       = std::__static_fancy_pointer_cast<__node_pointer>(__child);
+  if (__child == nullptr) {
+    __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__ptr));
+    __r = __ptr;
+    __nh.__release_ptr();
+  }
+  return iterator(__r);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle>
+_LIBCPP_HIDE_FROM_ABI _NodeHandle __tree<_Tp, _Compare, _Allocator>::__node_handle_extract(key_type const& __key) {
+  iterator __it = find(__key);
+  if (__it == end())
+    return _NodeHandle();
+  return __node_handle_extract<_NodeHandle>(__it);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle>
+_LIBCPP_HIDE_FROM_ABI _NodeHandle __tree<_Tp, _Compare, _Allocator>::__node_handle_extract(const_iterator __p) {
+  __node_pointer __np = __p.__get_np();
+  __remove_node_pointer(__np);
+  return _NodeHandle(__np, __alloc());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Comp2>
+_LIBCPP_HIDE_FROM_ABI void
+__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_unique(__tree<_Tp, _Comp2, _Allocator>& __source) {
+  for (iterator __i = __source.begin(); __i != __source.end();) {
+    __node_pointer __src_ptr = __i.__get_np();
+    auto [__parent, __child] = __find_equal(__src_ptr->__get_value());
+    ++__i;
+    if (__child != nullptr)
+      continue;
+    __source.__remove_node_pointer(__src_ptr);
+    __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__src_ptr));
+  }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle>
+_LIBCPP_HIDE_FROM_ABI typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh) {
+  if (__nh.empty())
+    return end();
+  __node_pointer __ptr = __nh.__ptr_;
+  __end_node_pointer __parent;
+  __node_base_pointer& __child = __find_leaf_high(__parent, __ptr->__get_value());
+  __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__ptr));
+  __nh.__release_ptr();
+  return iterator(__ptr);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _NodeHandle>
+_LIBCPP_HIDE_FROM_ABI typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(const_iterator __hint, _NodeHandle&& __nh) {
+  if (__nh.empty())
+    return end();
+
+  __node_pointer __ptr = __nh.__ptr_;
+  __end_node_pointer __parent;
+  __node_base_pointer& __child = __find_leaf(__hint, __parent, __ptr->__get_value());
+  __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__ptr));
+  __nh.__release_ptr();
+  return iterator(__ptr);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Comp2>
+_LIBCPP_HIDE_FROM_ABI void
+__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_multi(__tree<_Tp, _Comp2, _Allocator>& __source) {
+  for (iterator __i = __source.begin(); __i != __source.end();) {
+    __node_pointer __src_ptr = __i.__get_np();
+    __end_node_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, __src_ptr->__get_value());
+    ++__i;
+    __source.__remove_node_pointer(__src_ptr);
+    __insert_node_at(__parent, __child, std::__static_fancy_pointer_cast<__node_base_pointer>(__src_ptr));
+  }
+}
+#endif // _LIBCPP_STD_VER >= 17
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator __tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p) {
+  __node_pointer __np    = __p.__get_np();
+  iterator __r           = __remove_node_pointer(__np);
+  __node_allocator& __na = __node_alloc();
+  __node_traits::destroy(__na, std::addressof(const_cast<value_type&>(*__p)));
+  __node_traits::deallocate(__na, __np, 1);
+  return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l) {
+  while (__f != __l)
+    __f = erase(__f);
+  return iterator(__l.__ptr_);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k) {
+  iterator __i = find(__k);
+  if (__i == end())
+    return 0;
+  erase(__i);
+  return 1;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k) {
+  pair<iterator, iterator> __p = __equal_range_multi(__k);
+  size_type __r                = 0;
+  for (; __p.first != __p.second; ++__r)
+    __p.first = erase(__p.first);
+  return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const {
+  __node_pointer __rt = __root();
+  auto __comp         = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+    else
+      return 1;
+  }
+  return 0;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const {
+  __end_node_pointer __result = __end_node();
+  __node_pointer __rt         = __root();
+  auto __comp                 = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+      __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+    else
+      return std::distance(
+          __lower_bound_multi(__k,
+                              std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_),
+                              std::__static_fancy_pointer_cast<__end_node_pointer>(__rt)),
+          __upper_bound_multi(__k, std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_), __result));
+  }
+  return 0;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::iterator __tree<_Tp, _Compare, _Allocator>::__lower_bound_multi(
+    const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
+  while (__root != nullptr) {
+    if (!value_comp()(__root->__get_value(), __v)) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__root);
+      __root   = std::__static_fancy_pointer_cast<__node_pointer>(__root->__left_);
+    } else
+      __root = std::__static_fancy_pointer_cast<__node_pointer>(__root->__right_);
+  }
+  return iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__lower_bound_multi(
+    const _Key& __v, __node_pointer __root, __end_node_pointer __result) const {
+  while (__root != nullptr) {
+    if (!value_comp()(__root->__get_value(), __v)) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__root);
+      __root   = std::__static_fancy_pointer_cast<__node_pointer>(__root->__left_);
+    } else
+      __root = std::__static_fancy_pointer_cast<__node_pointer>(__root->__right_);
+  }
+  return const_iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::iterator __tree<_Tp, _Compare, _Allocator>::__upper_bound_multi(
+    const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
+  while (__root != nullptr) {
+    if (value_comp()(__v, __root->__get_value())) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__root);
+      __root   = std::__static_fancy_pointer_cast<__node_pointer>(__root->__left_);
+    } else
+      __root = std::__static_fancy_pointer_cast<__node_pointer>(__root->__right_);
+  }
+  return iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__upper_bound_multi(
+    const _Key& __v, __node_pointer __root, __end_node_pointer __result) const {
+  while (__root != nullptr) {
+    if (value_comp()(__v, __root->__get_value())) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__root);
+      __root   = std::__static_fancy_pointer_cast<__node_pointer>(__root->__left_);
+    } else
+      __root = std::__static_fancy_pointer_cast<__node_pointer>(__root->__right_);
+  }
+  return const_iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, typename __tree<_Tp, _Compare, _Allocator>::iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) {
+  using _Pp                   = pair<iterator, iterator>;
+  __end_node_pointer __result = __end_node();
+  __node_pointer __rt         = __root();
+  auto __comp                 = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __result = static_cast<__end_node_pointer>(__rt);
+      __rt     = static_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = static_cast<__node_pointer>(__rt->__right_);
+    else
+      return _Pp(iterator(__rt),
+                 iterator(__rt->__right_ != nullptr ? static_cast<__end_node_pointer>(std::__tree_min(__rt->__right_))
+                                                    : __result));
+  }
+  return _Pp(iterator(__result), iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const {
+  using _Pp                   = pair<const_iterator, const_iterator>;
+  __end_node_pointer __result = __end_node();
+  __node_pointer __rt         = __root();
+  auto __comp                 = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+      __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+    else
+      return _Pp(
+          const_iterator(__rt),
+          const_iterator(__rt->__right_ != nullptr
+                             ? std::__static_fancy_pointer_cast<__end_node_pointer>(std::__tree_min(__rt->__right_))
+                             : __result));
+  }
+  return _Pp(const_iterator(__result), const_iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, typename __tree<_Tp, _Compare, _Allocator>::iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) {
+  using _Pp                   = pair<iterator, iterator>;
+  __end_node_pointer __result = __end_node();
+  __node_pointer __rt         = __root();
+  auto __comp                 = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+      __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+    else
+      return _Pp(__lower_bound_multi(__k,
+                                     std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_),
+                                     std::__static_fancy_pointer_cast<__end_node_pointer>(__rt)),
+                 __upper_bound_multi(__k, std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_), __result));
+  }
+  return _Pp(iterator(__result), iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const {
+  using _Pp                   = pair<const_iterator, const_iterator>;
+  __end_node_pointer __result = __end_node();
+  __node_pointer __rt         = __root();
+  auto __comp                 = __lazy_synth_three_way_comparator<value_compare, _Key, value_type>(value_comp());
+  while (__rt != nullptr) {
+    auto __comp_res = __comp(__k, __rt->__get_value());
+    if (__comp_res.__less()) {
+      __result = std::__static_fancy_pointer_cast<__end_node_pointer>(__rt);
+      __rt     = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_);
+    } else if (__comp_res.__greater())
+      __rt = std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_);
+    else
+      return _Pp(__lower_bound_multi(__k,
+                                     std::__static_fancy_pointer_cast<__node_pointer>(__rt->__left_),
+                                     std::__static_fancy_pointer_cast<__end_node_pointer>(__rt)),
+                 __upper_bound_multi(__k, std::__static_fancy_pointer_cast<__node_pointer>(__rt->__right_), __result));
+  }
+  return _Pp(const_iterator(__result), const_iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder
+__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT {
+  __node_pointer __np = __p.__get_np();
+  if (__begin_node_ == __p.__ptr_) {
+    if (__np->__right_ != nullptr)
+      __begin_node_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__np->__right_);
+    else
+      __begin_node_ = std::__static_fancy_pointer_cast<__end_node_pointer>(__np->__parent_);
+  }
+  --__size_;
+  std::__tree_remove(__end_node()->__left_, std::__static_fancy_pointer_cast<__node_base_pointer>(__np));
+  return __node_holder(__np, _Dp(__node_alloc(), true));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_HIDE_FROM_ABI void swap(__tree<_Tp, _Compare, _Allocator>& __x, __tree<_Tp, _Compare, _Allocator>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
+  __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___TREE